The use of fluid under pressure from the high pressure side of the compressor to control the operation of the inlet valve to the compressor and thereby control the operation of the compressor is very well known. Some recent examples of such regulators are shown for example, in recently issued U.S. Pat. No. 5,388,967 issued Feb. 14, 1995 and U.S. Pat. No. 5,456,582 issued Oct. 10, 1995, both to Firnhaber et al. These controls require a number of different orifices and control lines to operate the system and pneumatically control the position of an inlet valve for the compressor in accordance with the air pressure in the receiver.
U.S. Pat. No. 5,533,867 issued Jul. 9, 1996 to Kinds discloses a similar type control that uses a pair of opposed springs to more accurately adjust the operating pressure.
U.S. Pat. 4,362,475 issued Dec. 7, 1982 to Seitz discloses a control system using air under high pressure from the receiver to move a piston and provides a blow down orifice leading into the inlet passage valve (blow down is the reduction in pressure when the compressor is shut down). This system also includes a bypass orifice as well as two other orifice type passages bringing air under receiver pressure into the control piston chamber.